Limp material pickup device

ABSTRACT

A device designed to lift a single ply of flexible sheet material from a stack. A pair of meshing gears rotatably mounted upon a support each carry an impaling means mounted on its periphery extending in converging relationship towards each other. A fluid motor mounted upon the support is drivingly connected through a crank arm to one of the gears, which upon actuation, will rotate one of the gears driving the other. Rotation of the gears causes the impaling means to move downwardly towards a stack of sheet material which can be positioned therebeneath, to penetrate and grasp therebetween, in a pinching or bunching motion, a single ply of said material from the stack. The fluid motor has its piston linearly adjustable in a slot formed in the crank arm, wherein the throw of the crank arm can be varied to finely adjust the amount of rotation of the gears, which in turn adjusts the depth of penetration or downward movement of the impaling means, so that the device will pick up only a single ply of material regardless of variations in thickness of material in different stacks.

Unit

Inventor William W. Littleiield El Paso, Tex. Appl. No. 860,587 Filed Sept. 241, 1969 Patented Sept. 28, 1971 Assignee Automatic Systems of America llnc.

El lPaso, Tex.

LIMP MATERIAL lPlCKlUlP DEVICE 7 Claims, 8 Drawing Figs.

U.S.Cl t 271/21 Int. Cl B6511 3/22 Field at Search 271/19, 20, 21, 24, 18

References Cited UNITED STATES PATENTS 6/1905 Miller 271/18 Primary Examiner-Joseph Wegbreit Attorney-Brufsky and Staas ABSTRACT: A device designed to lift a single ply of flexible sheet material from a stack. A pair of meshing gears rotatably mounted upon a support each carry an impaling means mounted on its periphery extending in converging relationship towards each other. A fluid motor mounted upon the support is drivingly connectedthrough a crank arm to one ot'the gears, which upon actuation, will rotate one of the gears driving the other. Rotation of the gears causes the impaling means to move downwardly towards a stack of sheet material which can be positioned therebeneath, to penetrate and grasp therebetween, in a pinching or bunching motion, a single ply of said material from the stack. The fluid motor has its piston linearly adjustable in a slot formed in the crank arm, wherein the throw of the crank arm can be varied to finely adjust the amount of rotation of the gears, which in turn adjusts the depth of penetration or downward movement of the impaling means, so that the device will pick up only a single ply of material regardless of variations in thickness of material in different stacks.

PATENTED SEP28 I9?! 3' 608) sum 1 OF 2 X n/ V INVENTOII 74 22 WILLIAM w. LITTLEFIELD BY /ufvc Md fla ATTORNEYS PATENTEDSP28l97| 3508,8230

SHEET 2 0F 2 66 62 WILLIAM w. LITTLEFIELD ATTORNEYS LIMP MATERIAL PICKUP DEVICE BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a device for grasping, lifting and transporting flat flexible sheet material one piece at a time, from a pile containing multilayers of the material.

2. Description of the Prior Art The pickup device of the present invention is particularly suited for use in the garment industry wherein the handling of fabrics are commonplace.

For example, prior to stitching fronts and backs of trousers together or stitching a pocket to a garment, a single ply of fabric is manually handled by lifting it from a stack and placing it upon another ply. If the handling of the fabric ply is automated, a substantial increase in production could be realized.

Heretofore, relatively impervious material such as paper, cardboard, metal and the like were handled by means of suction devices. Such devices are generally satisfactory for handling this type of material, but are not satisfactory if the material to be handled is porous, because in attempting to pick up from a pile or stack only one sheet at a time, the underlying layer or layers of material in the pile are disturbed.

Accordingly, attempts have been made to physically grasp one ply of porous fabric material from a multilayer stack by use of a pickup head carrying fabric impaling means which penetrate the stack to pick up one ply of material without disturbing the underneath layers. Such device is shown in U.S. Pat. No. 3,386,763. A pair of converging impaling means driven into a stack of fabric material, penetrate and grasp in a pincher movement a single ply of material from the stack. The single ply is then lifted and transported to a different location where it is superimposed upon another fabric ply prior to subsequent processing. The impaling means are moved by means of pneumatically inflatable tubes bearing against surfaces of the impaling means, which when inflated by fluid under pressure, drive the impaling means into a penetrating relationship with the fabric stack. However, the depth of penetration of the impaling means into the fabric stack is difficult to control and adjust to compensate for variations in thickness of material in different stacks to assure that only one ply of material is grasped from the stack.

SUMMARY OF THE INVENTION The limp material pickup device of the present invention utilizes a mechanical drive subject to a high degree of precise adjustment to effect control of the movement of a pair of converging impaling means, to assure that only one ply of material is penetrated, grasped and lifted from a fabric stack regardless of variations in thickness of the material handled.

The pickup device of the present invention employs a pair of meshing gears rotatably mounted upon a support, which is adapted to be positioned over a stack of flat, flexible fabric material. Fixed to the periphery of each gear is an impaling means having a downwardly extending needle. The impaling means are mounted on each gear in converging relationship towards each other. A fluid motor is pivotally mounted upon the support and is pivotally connected to a crank arm fixed to one of the gears. The fluid motor has a limited stroke, whereby when its piston is extended, it will cause the crank arm and associated gear to rotate through a limited arc. Rotation of one gear will cause rotation of the other gear in an opposite direction. Opposite rotation of the two gears will cause the needles of the impaling rireans to move downwardly towards the stack of fabric sheet material to penetrate the same in a downward and inward pinching motion to grasp a single ply therebetween. After the ply of material is grasped by the penetrating needles, the support and ply can be lifted and transported to another location where the ply can be deposited in a position for stitching to another ply of fabric. It is only necessary to actuate the fluid motor in an opposite direction to release the ply in proper position. Actuation of the fluid motor in an opposite direction will cause retraction of its piston. The retraction of the piston will cause oscillation of the crank arm in an opposite direction, which in turn will move the needles to release the ply of material it has grasped and pinched therebetween.

In order to assure that only a single ply of fabric is grasped and lifted from the stack, regardless of the thickness of the plies in the stack, two fine mechanical adjustments are provided. First, the oscillating crank arm connected to one of the gears is provided with an elongated slot. The piston of the fluid motor is slidably adjustable in the slot in the crank arm to vary the throw of the crank arm and the amount of rotation of the gears. Varying the amount of rotation of the gears will in turn vary the depth of penetration of the impaling needles carried by the gears into the stack of fabric material. Secondly, each needle is adjustably mounted in a support block by means of a threaded fastener, whereby the amount of extension of each needle from its support block and consequent penetration of the fabric stack can be varied by merely threading the fastener more or less.

Further objects and advantages of the invention will become more apparent from the following specification and claims, and from the accompanying drawings wherein:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a perspective view of the limp material pickup device of the subject invention;

FIG. 2 is a front view in elevation of the limp material pickup device of FIG. ll, illustrating the first step in its manner of use;

FIG. 3 is a front view in elevation similar to FIG. 2, illustrating a subsequent step of operation of the pickup device in which the impaling means of the device have been positioned so as to penetrate and grasp a single ply of fabric material;

FIG. 4, is a front view in elevation of the pickup device of the subject invention shown in FIG. 1, with certain portions broken away and illustrated in section;

FIG. 5 is a rear view in elevation of the pickup device shown in FIG. ll;

FIG. 6 is a top plan view of the pickup device shown in FIG.

FIG. 7 is a cross-sectional view taken substantially along the plane indicated by line 7-7 of FIG. 5 and more particularly, illustrating the pivotal connection of the piston of the fluid motor of the pickup device to the crank arm used to rotate the gears thereof; and

FIG. 8 is a perspective view of a portion of the impaling means used in the pickup device of the subject invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings in detail, wherein like numerals indicate like elements throughout the several views, the pickup device of the instant invention is generally indicated by the numeral MI.

The pickup device It) includes an L-shaped support 12 which is adapted to be positioned over a stack of flexible sheet material, such as fabric material. Support 12 includes an elongated upright leg 14 connected to a horizontal leg 16. Leg 16 has an elongated slot 18 cut therein through which impaling needles 20 and 22 are adapted to extend to penetrate and grasp in a downward and inward motion, a single ply of fabric material from a multilayer stack. After the material is penetrated and grasped by needles 20 and 22, a suitable device connected to bracket arms 2d and 26 of support I0 can be actuated to lift support 12 and the ply of material and transport for deposit of the material over another ply of fabric.

Each needle 20 and 22 is mounted in a support block 30 and extends outwardly through one end thereof. As shown in FIG. 8, the needle also extends through a threaded fastener 32 having a threaded portion 34 in which a pair of crisscross slots 36 and 38 are cut. The needle extends through a drilled hole 40 extending throughout the length of threaded fastener 32, which intercepts the crossover point of slots 36 and 38. Hole 40 is drilled slightly smaller than the diameter of the needle so that when the needle is inserted in the hole it will cause the threaded portion 34 to expand slightly and snugly grip the needle. Fastener 32 is threadedly received within support block 30 for a purpose which will become more apparent hereinafter.

Each of the needles and its associated support block are mounted in convergent relationship on the periphery of one of a pair of meshed gears 42 and 44. Each gear is fixed to a shaft 46 extending through upright leg 14 of support 12. Each shaft 46 is fixed in a bearing 48 and 50, respectively, mounted on each shaft 46 on the opposite or rearward side of upright leg 14 of support 12.

Pivotally secured to the rear of upright leg 14 of support 12 is a fluid motor generally designated by the numeral 60. Fluid motor 60 includes a fluid cylinder 62 having a piston rod 64 extending therefrom. Fluid is supplied to the interior of cylinder 62 on either side of a piston connected to a piston rod 64 through conduits 66 and 68.

Secured to piston rod 64 is a block 66' having an opening 68 therethrough. Bearing 70 is secured in opening 68. A pivot pin 72 extends through bearing 70 and has a threaded end portion 74 and an enlarged hear 76.

The head 76 of pivot pin 72 is slidably received within a T- shaped slot 78 formed in an upright crank arm 80 secured by welding or the like to bearing 70. Head 76 of pivot pin 72 can be adjustably positioned in T-shaped slot 78 by tightening nut 82 disposed on threaded portion 74 at the selected location of head 76 within the slot. Nut 82 when tightened, will clamp a washer 84 to bearing 70 to pull head 76 tightly against the front portion of the T-shaped slot 78 to retain it in adjusted position.

in operation, admission of fluid through conduit 68 will cause extension of piston rod 64 of fluid motor 60. Extension of piston rod 64 will cause rotation of crank arm 80 and rotation of bearing 48, shaft 46 and gear 44. Rotation of gear 44 in turn will cause rotation of gear 42 in an opposite direction. Rotation of gears 42 and 44 in opposite direction will cause needles and 22 to move downwardly and inwardly over a ply of fabric 90 and penetrate the same as shown in FIG. 3 with an inward pinching or bunching motion, thereby firmly grasping the ply of fabric. The pickup device 12 can then be raised or lifted and the ply 90 repositioned. Admission of fluid through conduit 66 will cause retraction of the piston within cylinder 62-and consequent retraction of piston rod 64. The retraction of piston rod 64 will cause oscillation of crank arm 80 in an opposite direction, causing gears 42 and 44 to rotate and return to their initial starting position. Rotation of gears 42 and 44 to their initial position will raise needles 20 and 22 above the lower edge of leg 16 of support 12. As the needles are raised, the ply of material 20 will tend to move upwardly with the needles until it strikes the lower edge of leg 16, which will strip the ply from the pickup device and deposit it at a preselected location.

In order to assure that only one ply of material is penetrated and grasped by the pickup device the depth of penetration of needles 20 and 22 can be adjusted. With the mechanical means employed in the present invention, this is possible in two ways. First, the head 76 of pivot pin 72 may be repositioned within the T-shaped slot 78 of crank arm 80. Lowering of the head 76 of pivot pin 72 within crank arm 80 will shorten the throw of the crank arm or its arc of rotation. Conversely, raising the head 76 of pivot pin 72 within slot 78 will lengthen the throw. Shortening or lengthening the throw of the crank arm 80 will respectively shorten or lengthen the period of revolution of each gear 42, 44 with a consequent reduction or increase in linear movement of needles 20 and 22 during its grasping motion.

Alternatively, further finer adjustment can be obtained by threading threaded member 32 into or out of its respective block 30. Threaded fasteners 32 provide flexibility in adjustment in that each individual needle 20 or 22 can be individually adjusted, whereas repositioning of pivot pin 72 within T-shaped slot 78 of crank arm provides adjustment of the depth of penetration of both needles simultaneously. The mechanical construction of the pickup device assures that only one ply of fabric will be penetrated and grasped by the apparatus.

lclaim:

1. Apparatus for use in grasping, lifting and transporting flexible flat sheet material from a stack of such material comprising:

a support,

a pair of elements in frictional driving engagement rotatably mounted on said support,

impaling means mounted on each of said rotatable elements adjacent the periphery thereof for movement relative to said support towards a stack of sheet material in response to rotation of said elements to penetrate and grasp a ply of said material in said stack, and

means for adjusting the amount of relative rotation of said pair of rotatable elements, thereby controlling the amount of movement of said impaling means relative to said support to control the depth of penetration of said impaling means into said sheet material stack.

2. Apparatus in accordance with claim 1 wherein said impaling means are mounted on said rotatable elements in converging relationship towards each other.

3. Apparatus in accordance with claim 1 wherein said rotatable elements comprise a pair of meshing gears.

4. Apparatus in accordance with claim 1 wherein said adjustment means includes means for rotating said pair of elements in opposite directions, said rotating means including a crank arm fixed to one of said rotatable elements,

a slot in said crank arm,

fluid motor means pivotally mounted on said support for oscillating said crank arm, and

means for pivotally connecting said fluid motor means to said crank arm, said pivotal connecting means being adjustably positioned in said crank arm slot whereby the throw of said crank arm can be varied to control the amount of relative movement of said impaling means relative to said support to thereby adjust the depth of penetration of said impaling means into said sheet material stack.

5. Apparatus for use in grasping, lifting and transporting flexible flat sheet material from a stack of such material comprising:

a support,

a pair of elements in frictional driving engagement rotatably mounted on said support, and

impaling means mounted on each of said rotatable elements adjacent the periphery thereof for movement relative to said support towards a stack of sheet material in response to rotation of said elements to penetrate and grasp a ply of said material in said stack, said impaling means includmg a block having a pair of spaced ends,

a threaded element adjustably threaded into one end of said block, and

a needle extending from the other end of said block and connected to said threaded element.

6. Apparatus in accordance with claim 1 wherein said support includes:

an upright leg,

a horizontal leg connected to said upright leg, said horizontal leg having an elongated slot,

said elements being rotatably mounted on said upright leg so that said impaling means extend through said elongated slot in response to rotation of said elements.

7. Apparatus for use in grasping, lifting and transporting flexible flat sheet material from a stack of such material comprising:

a support,

a needle extending from the other end of said block and connected to said threaded element whereby the extent of exposure of said needle and subsequent penetration of said sheet material stack can be controlled by rotation of said threaded element, and

means for adjusting the amount of relative rotation of said pair of rotatable elements, whereby the amount of movement of said impaling means relative to said support can also be controlled to further control the depth of penetration of said impaling means into said sheet material stack. 

1. Apparatus for use in grasping, lifting and transporting flexible flat sheet material from a stack of such material comprising: a support, a pair of elements in frictional driving engagement rotatably mounted on said support, impaling means mounted on each of said rotatable elements adjacent the periphery thereof for movement relative to said support towards a stack of sheet material in response to rotation of said elements to penetrate and grasp a ply of said material in said stack, and means for adjusting the amount of relative rotation of said pair of rotatable elements, thereby controlling the amount of movement of said impaling means relative to said support to control the depth of penetration of said impaling means into said sheet material stack.
 2. Apparatus in accordance with claim 1 wherein said impaling means are mounted on said rotatable elements in converging relationship towards each other.
 3. Apparatus in accordance with claim 1 wherein said rotatable elements comprise a pair of meshing gears.
 4. Apparatus in accordance with claim 1 wherein said adjustment means includes means for rotating said pair of elements in opposite directions, said rotating means including a crank arm fixed to one of said rotatable elements, a slot in said crank arm, fluid motor means pivotally mounted on said support for oscillating said crank arm, and means for pivotally connecting said fluid motor means to said crank arm, said pivotal connecting means being adjustably positioned in said crank arm slot whereby the throw of said crank arm can be varied to control the amount of relative movement of said impaling means relative to said support to thereby adjust the depth of penetration of said impaling means into said sheet material stack.
 5. Apparatus for use in grasping, lifting and transporting flexible flat sheet material from a stack of such material comprising: a support, a pair of elements in frictional drIving engagement rotatably mounted on said support, and impaling means mounted on each of said rotatable elements adjacent the periphery thereof for movement relative to said support towards a stack of sheet material in response to rotation of said elements to penetrate and grasp a ply of said material in said stack, said impaling means including a block having a pair of spaced ends, a threaded element adjustably threaded into one end of said block, and a needle extending from the other end of said block and connected to said threaded element.
 6. Apparatus in accordance with claim 1 wherein said support includes: an upright leg, a horizontal leg connected to said upright leg, said horizontal leg having an elongated slot, said elements being rotatably mounted on said upright leg so that said impaling means extend through said elongated slot in response to rotation of said elements.
 7. Apparatus for use in grasping, lifting and transporting flexible flat sheet material from a stack of such material comprising: a support, a pair of elements in frictional driving engagement rotatably mounted on said support, impaling means mounted on each of said rotatable elements adjacent the periphery thereof for movement relative to said support towards a stack of sheet material in response to rotation of said elements to penetrate and grasp a ply of said material in said stack, said impaling means including a block having a pair of spaced ends, a threaded element adjustably threaded into one end of said block, and a needle extending from the other end of said block and connected to said threaded element whereby the extent of exposure of said needle and subsequent penetration of said sheet material stack can be controlled by rotation of said threaded element, and means for adjusting the amount of relative rotation of said pair of rotatable elements, whereby the amount of movement of said impaling means relative to said support can also be controlled to further control the depth of penetration of said impaling means into said sheet material stack. 